Recently they online game developed on a network for enabling various types of games such as a role playing game (RPG) or a match-up game has been becoming more and more popular. In this type of online game, for the purpose to improve the attractiveness or value, for instance, in a network game fought between a group of combat planes and another group of combat planes, communications with comrade planes or with enemy planes are performed, and as a communication tool for that purpose, a chat system or a general telephone line is used for conversations.
In the case of conversations based on the chat system, in addition to operations for playing the game, however, entry of characters from a keyboard is required, so that the operations are complicated and troublesome, and further the response is rather slow, and sometimes the game can not progress smoothly. Further in the case of conversation over the general telephone line or the like, excessive economical burden is compelled to the players because of the current telephone rate system, so that these communication tools are not suited for a game requiring a long period of time to play. Although conversations among a plurality of participants are possible even now over the general telephone line, it is impossible to freely and temporally switch the communication mode to, for instance, person to person communication mode or person to multiple persons communication mode during multiple persons to multiple persons communication mode.
Japanese Patent Laid-Open Publication No. 2001-314657 discloses a network game system comprising a voice exchange means such as the Internet telephone or the like available between two persons, one as a navigator and the other as a player, and in this system voices are subjected to acoustic effects to introduce reality into the game. However, the technology disclosed in the publication is limited to person to person telephone communications, and the technology can not enable communications among multiple persons as that required in the match-up game. In addition, the acoustic effects are only application of acoustic pressure and tone control to voices of a telephone message, and therefore the technology is not sufficient for substantially improving realistic sensations or reality of a game.